Brake apparatus for bicycle

ABSTRACT

A brake apparatus for bicycle having a drop handle including a straight bar portion and bent bar portions to be mounted on the bent bar portion. The apparatus comprises a clip band for embracing the bent bar portion, a mounting bracket having an opening, a brake lever having a head inserted into the bracket from the opening and connected to one end of an actuating wire, and an auxiliary lever mounted on the inner side wall of the bracket and having portions extending in an L-form in parallel to the bent bar portion and straight bar portion respectively, with a coupling piece formed in the head of the auxiliary lever. Also disclosed are technique for pivotally supporting and assembling the bracket, brake lever and auxiliary lever by a lever pin and a fastening screw and a device for retaining the fastening screw in the lever pin against loosening.

Yoshigai ..'74/489 X Umted States Patent 1 [111 3,776,061

Yoshigai, Kiyokazu Dec. 4, 1973 BRAKE APPARATUS FOR BICYCLE PrimaryExaminer-Allan D. Hermann [75] Inventor: Yoshigai, l iiyokagu Osaka,Japan A"mey James Armsn'ong et 57 ABSTRACT [73] Asslgnee: Yosmg? Klka'Kmzoku 4 A brake apparatus for bicycle having a drop handle Osaka Japanincluding a straight bar portion and bent bar portions 22 Filed; No 15,1972 to be mounted on the bent bar portion. The apparatus comprises aclip band for embracing the bent bar por- [211 Appl' 306,906 tion, amounting bracket having an opening, a brake lever having a head insertedinto the bracket from the 30 Foreign Application priority i opening andconnected to one end of an actuating 4 wire, and an auxiliary levermounted on the inner side June I 1972 Japan 47/71138 wall of the bracketand having portions extending in 52 us. Cl. 74/480 R, 74/489 in Parallelthe bar and 51 Int. ii i k 23/06 B621 3/02 might bar respectively withPiece 58 Field of Search 74/480 R 489 fumed the head the auxiliary 'Alsodisclosed are technique for pivotally supporting [56] References Citedand assembling the bracket, brake lever and auxiliary UNITED STATESPATENTS lever by a lever pin and a fasteningscrew and a device 3 40310/1968 i 74/489 x for retaining the fastening screw in the lever pin3:596:30 8/1971 Ozak against loosening 2 Claims, 8 Drawing FiguresPATENIEUnFn 4 I973 3 776 061 U SHEET 5 [IF 5 Fig 8 (Prior Art) BRAKEAPPARATUS FOR BICYCLE BACKGROUND OF THE INVENTION The present inventionrelates to a brake for bicycles, more particularly to a brake apparatusfor bicycles of the drop handle type.

It is known that steering handles of bicycles are generally grouped intothree types, i.e., up handle, flat handle and drop handle. Among these,the drop handle is used for racing bicycles which are adapted for highspeed cycling as in track racing and roadracing as well as for touringbicycles for cycling a long distance. The drop handle assures stable andefficient cycling free of fatigue because of its functional form whichenables the rider to grasp the handle at a selected position and in anoptimum posture suitably determined depending upon cycling purposes andcycling conditions such as a speed change from low to high or going up aslope.

The drop handle comprises an approximately horizontal straight barportion mounted on a fork stem of the front wheel and extendingsubstantially at right angles to the fork stern and bent bar portionsprojecting forward from the opposite ends of the straight bar portionand bent in a U-like shape.

As well-known, the brake lever is mounted approximately at the middle ofthe bent bar portion or at a slightly upper part thereof by means of abracket. In the case where the brake lever is mounted at such specificposition, the hand grasping the handle at the desired portion thereof inaccordance with cycling purposes and conditions peculiar to the drophandle may possibly be inaccessible to the brake lever depending uponwhere the hands are positioned on the handle. Accordingly, when therearises'a need to'apply the brake, the hand has to be removed from thehandle to operate the brake lever or the hand on the handle has to beshifted to operate the brake lever. Thus the rider must-operate thebrake in an unstable posture and, in-an emergency, fails to apply thebrake with appropriate timing with the possibility of the bicyclefalling or colliding with another bicycle. I

A brake apparatus for bicycles of the drop handle type has been proposedas disclosed'in U.S.- Pat. No. 3403577 (granted to the presentapplicant) which includes an auxiliary lever operatively associated withthe brake lever on the drop handle so as to make it sure all the timethat the brake lever can be operated by the hand which is grasping thedrop handle at the desired portion thereof. This type of apparatus hasso far won popularity.

More specifically, the improved brake apparatus principally comprises aclip band for securing the apparatus to the handle, a bracket, a brakelever, and an auxiliary lever. The bracket is in the form of a boxhaving an opening from which the opposite side walls of the brake leverhead are inserted. The auxiliary lever, approximately L-shaped, isattached to one side wall of the bracket. The bracket and the levers aresupported on a lever pin extending therethrough and mounted in place bymeans of a bush, a fasteningscrew and a lock member, whereby the brakelever and auxiliary lever are pivotably supported on the lever pin. Theauxiliary lever is formed at its front end with a coupling piece whichis interposed between the engageable head of the its midportion toprovide a part positioned in parallel with the straight bar portion.

Thus, when the brake is to be applied by the hand grasping the straightbar portion of the handle, the fingers can be placed on that portion ofthe auxiliary lever which is parallel to the straight bar portion of thehandle. It is therefore possible to operate the brake lever by movingthat portion and thereby turning the coupling piece forward about thelever pin (lock member).

However, the improved brake apparatus is complex in its construction forsupporting the three members,

and the fastening screw and the lock member exposed from the oppositeside walls of the bracket deteriorate its commercial value. Further inthe case where the handle is grasped in accordance with cyclingconditions and purposes, for example when travelling at a speed higherthan 30 km/h or when going up a steep slope, the bracket portion has tobe grasped with the handle brought closer toward the breast of the riderso that he may forcibly push down the pedal. On such occasion, the lockmember projecting from the outer side wall of the bracket will contactthe palm and cause a pain, hence the hand can not grasp the bracketfirmly.

For these reasons, another construction has been commercially providedfor supporting the abovementioned three members which no longerincorporates an externally projecting lock member as shown in FIG. 8.

According to this construction, the lever pin 13' extends through anauxiliary lever 14, a bracket 4 and a brake lever 7. The lever pin 13'is formed with a transverse hole 13a for passing and securing screw forforcing up a clip band 5. The auxiliary lever 14' is fitted with a pairof flanged nylon bushes 17'. The lever pin 13 has ablind bore 13d formedwith a female screw-thread in which a coil spring18 is placed. Afastening screw 15 is screwed into the blind bore 13d with a springwasher 19 disposed between the lever pin 13 and the head of the screw15. The securing screw 20 is passed through the hole 13c and screwedthrough a seat plate 21 provided on the clip band 5', to force up theband 5 and secure the brake apparatus to the drop, handle.

With this support construction, the auxiliary lever 14, when operated,may possibly be urged in the direction of arrow P' shown, causing thebracket 4 to be pushed leftward in the drawing by the flange of nylonbush 17 which is in direct contact with one wall 4c of the bracket 4'.This will produce a great clearance between the bracket 4 and the nylonbush 17, permitting the coupling piece on the head of auxiliary lever 14to be disengaged from the head of brake lever 7'. Further the head 20aof the screw 20'-forcing up the clip band 5 will be inclinedto contactone side wall 11a of the brake lever because the securing screw 20extends loosely through the hole l3e', preventing smooth pivotalmovement of the brake lever 7 to render the brake substantiallyinoperative. Thus the construction is not suitable for a modern brakeapparatus which must assure high safety.

SUMMARY OF THE INVENTION A main object of this invention is to provide abrake apparatus including ingenuous means for supporting a bracket, abrake lever and an auxiliary lever so as to always assure proper brakelever operation which is essential to the brake apparatus and to permitthe auxiliary lever to be operated properly all the time for a brakingaction whatever part of the handle may be grasped by the hand, theapparatus thus afiording high safety in cycling.

Another object of this invention is to provide a brake apparatus whereinthe construction for supporting the three members by a lever pin, bushand the like includes means by which a fastening screw screwed into thelayer pin from one side thereof can be prevented from loosening due tovibration during travelling on a bad road or due to a long period ofuse, so as to secure safety in cycling.

Other objects and advantages of this invention will become more apparentfrom the following description of an embodiment thereof with referenceto the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a brakeapparatus of this invention mounted on a drop handle at its rightportion;

FIG. 2 is a side elevation of the same;

FIG. 3 is an enlarged sectional view of the same along the line III-IIIin FIG. 2;

FIG. 4 is an enlarged sectional view particularly showing a pivotallysupporting construction;

FIG. 5 is a cross sectional view showing a locking spring and afastening screw in arresting engagement;

FIG. 6 is an exploded perspective view showing con stituent parts of thebrake apparatus of this invention;

FIG. 7 is a sectional view of the support construction shown in FIG. 4,the view illustrating the auxiliary lever portion on an enlarged scale;and

FIG. 8 is a sectional view showing a conventional corresponding to FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings,particularly to FIGS. 1 to 3, a drop handle mounted on a fork stem 1comprises a straight bar portion 2 positioned substantially horizontallyat right angles to the fork stem 1 and bent bar portions 3 respectivelyextending forward from the opposite ends of the straight bar portion 2substantially in U-form.

The present braking apparatus is mounted on the bent portion 3approximately at its midportion by means of a bracket 4 and a clip band5. The bracket 4 is in the form of a box having a front opening 4a and ahole 4b in its rear top portion for passing a brake wire 6.

A brake lever 7 is provided in its head 7a with a connector 8 to whichone end of an unillustrated inner wire included in the brake wire 6 issecured. Opposite side walls 11 and 11a of the head 7a are inserted intothe bracket 4 through the opening 4a and supported on a lever pin 13 bymeans of flanged nylon bushes l2 and 12.

An auxiliary lever 14 hasa portion 14a parallel to the bent portion 3and a portion 14b parallel to the straight bar portion 2 of the handlewhich are substantially L- shaped. An intermediate part of the portion144 is pivoted by a fastening screw 15 to one side wall 40 of the andthe end face'4d of opening of the bracket-4.

As will be apparent from the'above description, the bracket 4, brakelever 7 and auxiliary lever 14 are supported on the lever pin 13 andretained in position by the fastening screw 15. The lever pin 13 hassuch length as to extend through the above-mentioned three members. Asshown in FIG. 6, one end of the lever pin 13 has a stepped portion 13ato provide a reduced diameter portion 13b, which is formed with a blindbore 13d formed with a female screw-thread 13c extending from the end ofthe reduced diameter portion 13b to an intermediate part. A metal washerl6 and a flanged bush 17 made of a rigid resin such as nylon are fittedaround the reduced diameter portion 13b. A coil spring 18 is placed inthe blind bore 13d, and the fastening screw 15 is driven therein with aspring washer 19 positioned on the end face of the reduced diameterportion. In this way, the brake lever 7 and auxiliary lever 14 arepivotally supported on the lever pin 13.

Since the auxiliary lever 14 is pivotally supported on the reduceddiameter portion 13b with the rigid resin bush 17 interposedtherebetween, the lever 14 can be pivotally moved with minium wear anddamage. The use of the washer 16 made of metal is advantageous, becauseit is less susceptible to deformation for the reason to be describedlater, when brought into engagement with the stepped portion 13a.

As seen in FIG. 7, the length l of the reduced diameter portion 13b issmaller than the total length L, i.e., the thickness of the metal bush16 plus the length of the bush l7.

The lever pin 13 is formed, substantially at its midportion, with a hole13c extending transversely through the pin 13 for passing a securingscrew 20 for forcing up the clip band 5. The hole 13c has such diameterthat the securing screw 20 can pass therethrough loosely.

The clip band 5 is provided with a seat plate 21 retained thereonthrough engagement with openings 5b and 5b formed in its opposite wallends 5a and 5a. The seat plate 21 has a threaded hole 210 in which thesecuring screw 20 is screwed in.-

The head 7a of the brake lever 7 is inserted into the bracket 4 throughits opening 44, with the opposite side walls 11 fitted to the side walls40 of the bracket 4. The lever pin 13 is then inserted into the bracket4 and the head 7a from one side. The clip band 5 is fitted around thehandle bent portion 3 approximately at its midportion. The opposite sidewalls 5a and 5a of the clip band 5 are fitted onto the inner faces ofopposite side walls 40, 4c of the bracket 4. The securing screw 20 ispassed through the hole 13c of the pin 13 and screwed into the threadedhole 210 of the seat plate 21. The clip hand 5 thereby forced upward nowfirmly embraces the bent portion 3 of the handle, whereby the assemblyis held in position as seen in FIG. 3. t

The coil spring 18 is then placed into the blind bore 13d of the leverpin 13 and the washer 16 is fitted around the reduced diameter portion13b of the lever pin 13. The auxiliary lever 14 with a bush l7 fittedtherein is mounted on the pin I3,and the fastening screw 15 is screwedinto the blind bore 13d with the spring washer l9 interposed between thebush and the screw head.

Since the combined length L of the washer l6 and bush 17 is greater thanthe axial length l of the reduced diameter portion 13b, the pressingforce F exterted by the fastening screw 15 driven in'acts on the bush l7through the spring washer 19 as shown in FIG. 7 and further on thewasher 16 by way of the bush 17.

Because the lever pin 13 is formed with a stepped portion 130, thepressing force F acting on the washer 16 is exerted on the steppedportion 13a, which is subjected to a counteracting force Fproduced'in-the opposite direction when the fastening screw 15 is drivenin, with the result that the washer 16 is firmly clamped between thestepped portion 13a and the bush 17. Thus when the fastening screw 15 isdriven in to the greatest extent, the stepped portion 13a will be flushwith the outer face of one side wall 40 of the bracket 4 as seen in FIG.4.

For this reason, the auxiliary lever 14 is pivotably supported with thedistance l-l between the washer l6 and the flange 17a of the bush l7kept constant all the time as illustrated in FIG. 7.

Thus when a lateral external force is exerted as shown by an arrow P inFIG. 7 by the auxiliary lever 14 when it is operated, the bracket 4 isfree of the resulting pressure because the washer 16 is held against thestepped portion 13a, without any relative lateral displacement of thelever pin 13. Accordingly, the distance H is kept constant and shake ofthe auxiliary lever 14 is precluded.

Further the securing screw 20 extending through the lever pin 13 andscrewed into the seat plate 21 retains the pin 13 in position, while thewasher l6zheld against the stepped portion 13a keeps the bracket 4freefrom the pressure to be otherwise exerted by the external force asdescribed above. Consequently, the brake lever 7 will not slide on thelever pin 13, assuring that one side wall 11a of the brake lever 7 willbe free of contact with the head 20a of the securing screw 20,permitting accurate and smooth pivotal movement of the brake lever 7 allthe time to achieve safety during cycling.

According to this invention, it is assured thatthe fastening screw 15will be held in engagement with the lever pin 13 against loostening bythe construction shown in FlGS. 4 and 5 in which the winding directionof the coil spring '18 placed in the-blind bore 13d is opposite to thedirection in which the male screw-thread 15a of the fastening screwextends (i.e. if the former is left-handed, the latter is right-handed),the fastening screw 15 being formed, at its end, with a cutout steppedportion 15b for retaining one end 18a of the coil spring 18.

When the fastening screw 15 is driven into the blind bore 13d with thecoil spring 18 placed therein, the coil sping 18 will be compressed bythe fastening screw 15. At this time, since thehand of coil spring 18 isopposite to that of the screw, the stepped portion 15b will not arrestone end 18a of the coil spring 18 but moves past the same, permittingthe'end face 150 of the screw 15 to compress the spring 18 in slidingcontact with part of the end 18a. If the spring 18 and the screw 15werev handed in the same direction, the stepped portion 15b would strikeagainst one end 18a of the spring to untwist the spring 18 as'thefastening screw is driven in, with the result that the fastening screw15 would be prevented from further inward movement. The presentconstruction is free of such problem.

After the fastening screw 15 has been screwed to its final position, therestoring force of the compressed spring 18 acts in the axital directionof the fastening screw 15, with one end 18a of the spring in engagementengagement between the end 18a and the stepped porj tion 15b preventloosening of the fastening screw 15 from the lever pin 13, even when itis subjected to marked vibration while the bicycle is driven on a badroad, eliminating shake of the auxiliary lever 14 and the resultinginaccurate braking operation.

- According to this invention, the brake lever 7 mounted on the bent barportion 3 of the drop handle by means of bracket 4 can be pivotallymoved about the lever pin 13 by turning the tail end of the lever 7 in acounter-clockwise direction in FIGS. 1 and 2 as in usual manner, wherebythe brake wire 6 connected at its one end to the connector 8 is pulledthrough the guide opening 4a of the bracket 4 to pressbrake shoesagainst the rim for a braking action.' Thus if the drop handle isgrasped by the hand at such position that its fingers are engageablewith the lever 7, the lever 7 per se is operated to actuate the brake asin the conventional device.

In the case where the hand gripping the handle is not accessible to thebrake lever 7 as when the straight bar portion 2 of the handle isgrasped or the bent bar portion is gripped in proximity with thestraight bar portion 2 away from the bracket 4, the auxiliary lever 14will be operated to actuate the lever 7.

Since the auxiliary lever 14 includes portions 14a and 14b formed inL-form and positioned substantially in parallel with the bent barportions 3 and straight bar portion2 respectively, the fingers of thehand grasping the handle can be placed directly on the portion 14a or14b to pivotally move the auxiliary lever 14 about the lever pin 13,causing its coupling piece to push the head 7a of the lever 7. Throughthis movement, the lever 7 is pivotally moved about the lever pin 13 aswhen the tail end 7c is operated. The brake shoes can be actuatedthrough the wire 6.therefore. Conventionally, the hand grasping thehandle, if inaccessible to the lever 7, has to be slidingly moved towardthe lever 7 to manipulate the same or the hand has to be removed fromthe handle to operate the lever 7. The provision of the portions 14a and14b and that symmetrically on either side of the handle has eliminatedsuch instability or possible danger, no matter what part of the handlemay be grasped, making it possible to'operate the lever 7 accurately andquickly without losing the braking timing by utilizing the auxiliarylever 14 to assure safety.

Various advantages are assured by the construction for povotallysupporting the bracket 4, brake lever 7 and auxiliary lever 14 whichcomprises the lever pin 13 extending through these members and havingthe stepped portion 13a, the lever pin 13 carrying thereon washer 16 infitting engagement'with the stepped portion 13a and nylon bush 17positioned externally of the washer 16, with the fastening screw 15screwed in the blind ,bore 13d of the lever pin 13. For instance, the

' bracket 4 has an improved commercial value because it does not have ascrew head projecting therefrom which heretofore caused a pain in thepalm if the bracket was grasped. Further when the fastening screwtransversely, the auxiliary lever 14 will exert an external force on thestepped portion 13a by way of the washer 16, without pressing thebracket 4 on the lever pin 13. Consequently, it is assured that the head20a of the securing screw 20 will not contact the side wall of the brakelever 7, permitting the brake lever 7 to rotate smoothly all the time.The constant distance always maintained between the washer l6 and theflange 17a of the brake bush 17 serves to eliminate shake of theauxiliary lever 14 and prevent the disengagement of the coupling piece14c from the head 7a of the brake lever for safety cycling and accuratebraking action.

Loostening of the fastening screw is prevented by the restoring force ofthe coil spring 18 placed in the blind bore 13d of the lever pin 13 aswell as by the arresting engagement between one end 18a of the coilspring 18 with the stepped portion 15b. The pivotable members are thussupported reliably all the time even if subjected to vibration or thelike. The coil spring 18 winding in a direction opposite to the hand ofhelical thread of the fastening screw 15 enables the fastening screw 15to be screwed into the blind bore 13d free of trouble.

What is claimed is:

l. A brake apparatus for a bicycle having a drop handle including astraight bar portion and bent bar portions to be mounted on the bent barportion comprising a clip band for embracing the bent bar portion havinga seat plate, a mounting bracket having an opening, a brake lever havinga head inserted into the bracket from the opening and connected to oneend of an actuating wire, and an auxiliary lever mounted on the innerside wall of the bracket and having portions extending in an L-form inparallel with the bent bar portion and the straight bar portionrespectively, the auxiliary lever having a coupling piece formed in itshead, the bracket, the brake lever and the auxiliary lever beingsupported on a lever pin extending therethrough, the lever pin beingformed at its intermediate portion with a hole transversely of the leverpin for passing a screw and having a stepped portion to deifine areduced diameter portion at its end, the reduced diameter portion beingprovided with a blind bore formed with a female screwthread andextending in its axial direction, a metal washer and a flanged rigidresin bush being fitted on the reduced diameter portion with theauxiliary lever pivotally supported between the metal washer and theflange of the rigid resin bush, a fastening screw being screwed in theblind bore such that the pressure of the screwedin fastening screw actson the metal washer to engage the metal washer with thestepped portionand thereby retain the washer and the flange of the bush in constantrelation.

2. The brake apparatus for a bicycle as set forth in claim 1 wherein theblind bore has received therein a coil spring whose winding extends indirection opposite to the hand of male screw-thread of the fasteningscrew and the fastening screw is formed in its distal end with anarresting stepped portion so as to permit the screwed-in fastening screwto compress the spring, which in turn exerts its restoring force on thearresting stepped portion with one end of the spring in engagement withthe arresting stepped portion to prevent loosening of the fasteningscrew.

' i 0' l t

1. A brake apparatus for a bicycle having a drop handle including astraight bar portion and bent bar portions to be mounted on the bent barportion comprising a clip band for embracing the bent bar portion havinga seat plate, a mounting bracket having an opening, a brake lever havinga head inserted into the bracket from the opening and connected to oneend of an actuating wire, and an auxiliary lever mounted on the innerside wall of the bracket and having portions extending in an L-form inparallel with the bent bar portion and the straight bar portionrespectively, the auxiliary lever having a coupling piece formed in itshead, the bracket, the brake lever and the auxiliary lever beingsupported on a lever pin extending therethrough, the lever pin beingformed at its intermediate portion with a hole transversely of the leverpin for passing a screw and having a stepped portion to deifine areduced diameter portion at its end, the reduced diameter portion beingprovided with a blind bore formed with a female screw-thread andextending in its axial direction, a metal washer and a flanged rigidresin bush being fitted on the reduced diameter portion with theauxiliary lever pivotally supported between the metal washer and theflange of the rigid resin bush, a fastening screw being screwed in theblind bore such that the pressure of the screwed-in fastening screw actson the metal washer to engage the metal washer with the stepped portionand thereby retain the washer and the flange of the bush in constantrelation.
 2. The brake apparatus for a bicycle as set forth in claim 1wherein the blind bore has received therein a coil spring whose windingextends in direction opposite to the hand of male screw-thread of thefastening screw and the fastening screw is formed in its distal end withan arresting stepped portion so as to permit the screwed-in fasteningscrew to compress the spring, which in turn exerts its restoring forceon the arresting stepped portion with one end of the spring inengagement with the arresting stepped portion to prevent loosening ofthe fastening screw.